Panel joint construction

ABSTRACT

A panel joint construction having a first panel with a first rearwardly directed flange portion and a second panel having a second rearwardly directed flange portion terminating in an end sector disposed rearwardly of the first panel. A panel clip receiver element secured to one panel and a panel clip secured to the other with the panel clip engaged within the panel clip receiver. The panel clip receiver element having a base portion secured to one panel and two forwardly extending receiver sidewalls each terminating in inwardly rearwardly directed locking flanges. The panel clip secured to the other panel having an anchoring wall and a projecting tongue extending into the panel clip receiver between the locking flanges. Adjustable means permitting variable locking penetration of the projecting tongue into the receiver. The forwardly extending receiver sidewalls may be inclined transversely inwardly toward each other at an angle of about 2* to 15* with respect to a plane perpendicular to the receiver base. The included angle between the locking flanges and the adjacent receiver sidewall being about 25* to 45*.

United 8tates 1881M [72] Inventor LawrenceT. Vance [54] PANEL JOlNTCONSTRUCTION 10 Claims, 6 Drawing Figs.

[52] US. Cl 287/189.36

52/588, 287/189.35, 85/88 [51] lnt.Cl F161) 5/110 [50] Field of Search287/189.36

R, 189.36 C, 189.36 D, 189.36 F, 189.36 1-1, 20.92 C, 20.92 G, 189.35;52/588, 594, 384, 385, 538;

3,332,192 7/1967 Kessler et al 52/588 X 3,408,786 11/1968 Snyker 52/544X 3,436,881 4/1969 Schlecht ..287/l89.36 D X Primary Examiner-David J.Williamwossky Assistant Examiner-Wayne L. Shedd AltorneyArnold B.Silverman ABSTRACT: A panel joint construction having a first panel witha first rearwardly directed flange portion and a second panel having asecond rearwardly directed flange portion terminating in an end sectordisposed rearwardly of the first panel. A panel clip receiver elementsecured to one panel and a panel clip secured to the other with thepanel clip engaged within the panel clip receiver. The panel clipreceiver element having a base portion secured to one panel and twoforwardly extending receiver sidewalls each terminating in inwardlyrearwardly directed locking flanges. The panel clip secured to the otherpanel having an anchoring wall and a projecting tongue extending intothe panel clip receiver between the locking flanges. Adjustable meanspermitting variable locking penetration of the projecting tongue intothe receiver. The forwardly extending receiver sidewalls may be inclinedtransversely inwardly toward each other at an angle of about 2 to 15with respect to a plane perpendicular to the receiver base. The includedangle between the locking flanges and the adjacent receiver sidewallbeing about 25 to 45.

PAIENTEU SEP 1 4 i9?! SHEU 2 [IF 2 FIG. 2.

PANEL JOINT CONSTRUCTION BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to a panel clip assembly for adjustablyjoining adjacent panels and more specifically this invention relates toa uniquely configurated panel clip element adapted to be presecured toone panel and received within a panel clip receiver element which isadapted to be presecured to the other panel in forming a joint betweenadjacent panels.

2. Description of the Prior Art Numerous means of joining panel elementsto establish exterior wall structures as well as interior partitionwalls have been known. Various forms of hardware adapted for effectingjoinder between overlapping or abutting panel edges have been provided.

One difficulty encountered with respect to a number of panel-joiningelements is the lack of adjustability provided within the anchoringhardware. Adjustment of the locked relative position of one panel withrespect to the other, therefore, cannot be readily effected. Also,numerous panel-joining components require extensive effort in the fieldin order to first secure the joint-forming hardware to the panel edges.Also, frequently extensive joining effort is required in the field afterthe initial affixation has been completed in order to effect final paneljoinder.

In such installations economic considerations make it important to limitthe amount of required field labor to an absolute minimum, and also tocarefully control the cost of materials.

Another problem is the aesthetically unpleasing appearance of paneljoints established by many known systems.

An additional inconvenience frequently encountered is the need to employdifferent hardware for header and sill attachment than that employed inthe vertical joints between adjacent panels.

SUMMARY OF THE INVENTION The joint-forming elements of the presentinvention solves the previously enumerated problems in an economical andeffective fashion.

This invention provides complementary relatively adjustableinterengaging panel clip and panel clip receiver elements which may beconveniently and economically made in a conventional manner, as byextrusion.

The panel clip element has an anchoring wall, a serrated projectingtongue and a transitional wall connecting the anchoring wall with theserrated projecting tongue. The projecting tongue has a rearwardlydisposed end provided with outwardly diverging pilot surfaces adapted toengage the panel clip receiver and guide the tongue in the receiveropening. Each serration has a first serration-defining face orientedgenerally perpendicular to the longitudinal axis of the tongue and asecond serration-defining face oriented generally parallel to the pilotsurface portion disposed on the same side of the longitudinal tongueaxis.

A generally channel-shaped panel clip receiver has a base portion and apair of spaced sidewalls extending forwardly from opposite sides of thebase portion and a pair of angularly rearwardly disposed locking flangesconnected to the forward ends of said forwardly directed sidewalls andterminating in free ends spaced from each other and defining thereceiver opening. The included angle between the locking flanges andsaid forwardly directed sidewalls is preferably about 25 to 45.

It is an object of this invention to provide a panel joint constructionwherein adjacent panel members may be adjustably secured to each otherby means of panel clip components having two parts which are adapted tobe presecured to the panels to be joined.

It is a further object of this invention to provide a panel clipassembly having component parts which are adapted to be economicallymanufactured and installed and permit adjustable interengagement betweenthe respective elements to permit panel securement in a predeterminedposition relative to adjacent structural elements.

It is another object of this invention to provide a panel clip assemblywherein the same components may be employed to secure joints betweenadjacent panels as well as header or sill joints.

It is yet another object of this invention to provide such a panel clipassembly which will provide an aesthetically pleasing joint and reducethe amount of field labor required and yet provide readily effectedlocking engagement.

These and other objects of this invention will be more fully understoodfrom the following description of the invention, on reference to theillustrations appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view showinga portion of a wall constructed in accordance with this invention.

FIG. 2 is a fragmentary sectional view of the wall construction of FIG.1 taken through 22.

FIG. 3 is a fragmentary sectional view of the wall construction of FIG.1 taken through 33.

FIG. 4 is a cross-sectional view of a form of panel clip receiver ofthis invention.

FIG. 5 is a cross-sectional view of a form of panel clip of thisinvention.

FIG. 6 shows a partial sectional detail of the locking engagementprovided by this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more specificallyto the drawings with reference to FIGS. 1 through 3, it is seen that aribbed wall construction 2 is formed from a number of plastic panels 4which are joined at adjacent ends to provide vertical joints 6. A detailof a verticaljoint 6 is shown in FIG. 3. (Solely for simplicity ofdescription, as used herein, the terms forward" and forwardly and wordsof similar import shall refer to the direction toward which the exposedsurface of wall construction 2, as shown in FIG. 1, faces and the termsrear and rearwardly" and words of similar import shall refer to thedirection toward which the concealed or unexposed surface of wallconstruction 4 faces.) As is there illustrated, a first panel element 10has a first generally rearwardly directed flange portion 12. An adjacentsecond panel 14 has a second generally rearwardly directed flangeportion 16 which terminates in an end sector 18 disposed rearwardly ofthe first panel 10. First panel 10 has a forwardly exposed surface 20and a rearwardly exposed surface 22. Second panel 14 has a forwardlyexposed surface 24 and a rearwardly exposed surface 26. For convenienceof reference these surfaces 20, 22, 24 and 26 will be considered asextending the full extent of the respective panels l0, 14.

A panel clip 30 as shown is secured to first flange 12 by means of arivet 32. A panel clip receiver 40 as shown is secured to end sector 18of first panel element 10 by means of a rivet 42. This feature of theinvention permits a reduction in the amount of effort required in thefield by facilitating factory presecurement of the panel clip 30 andpanel clip receiver 40 to the respective panels l0, 14. This may beaccomplished by the preferred mechanical fastening means, such as rivet32, 42, or by other suitable means including adhesive materials.

Referring now more specifically to the detailed configuration of thepanel clip 30 and panel clip receiver 40, reference is made to FIGS. 4and 5. The panel clip receiver 40 has a base portion 44 and forwardlyextending receiver sidewalls 46 which terminate in rearwardly andtransversely inwardly directed locking flanges 48. The receiversidewalls 46 are preferably inclined slightly inwardly toward each otherwith respect to planes perpendicular to base element 44 at the base ofthe sidewalls 46. This inclination is represented by the angle A in FIG.4 and is preferably about 2 to 15". In order to provide for resilientdeflection of the locking flanges 48 during panel clip engagement, thereceiver 40 is preferably made of thinner material than panel clip 30.

The locking flanges 48 preferably taper toward their free ends 50 whichare disposed in spaced relationship with respect to each other anddefine receiver opening 52 therebetween. The included angle B between areceiver sidewall 46 and the adjacent connected locking flange 48 ispreferably about to 45 in order to'provide for ease of insertion of thepanel clip and effective locking engagement between the clip 30 andreceiver 40.

The panel clip receiver is preferably provided with a substantiallyuniform cross-sectional configuration throughout its longitudinal extentwith or without preformed fastener-receiving openings where required ordesired. This may be conveniently accomplished by extrusion, forexample. The clip may be made from a suitable meal, such as aluminum,plastic or other material possessing sufficient strength and resiliency.

The panel clip 30 has an anchoring wall 60, a projecting tongue 62 andan interposed connecting transitional wall 64. The projecting tongue 62terminates in a free end 66 having pilot or guide surfaces 68 onopposite sides thereof. A plurality of integrally formed serrations 70are formed on the transverse sidewalls of the projecting tongue 62 whichis preferably substantially rigid. In the form shown the serrations ofone wall are axially aligned with and coextensive with the serrations ofthe other wall to provide symmetry about a plane through thelongitudinal tongue axis. Each serration defines a recess 72 between aforwardly exposed face 74 which is disposed substantially perpendicularto the longitudinal axis of projecting tongue 62 and an angularlyforwardly directed face 76 originating at the transverse inner portionof the forwardly exposed face 74. In the form shown the maximumtransverse diameter of the tongue 62 is greater than the thickness ofeither anchoring wall 60 or transitional wall 64. The panel clip elementmay be conveniently made in such fashion that it has a substantiallyuniform cross-sectional configuration throughout its longitudinal extentwith or without preformed fastener-receiving openings.

The receiver opening 52 defined between free ends 50 of panel clipreceiver 40 is not as wide as the maximum transverse diameter ofprojecting tongue 62. In effecting the joint shown in FIG. 3 the panelsl0, 14 are first aligned so that projecting tongue 62 of panel clip 30is aligned with the receiver opening 52 in panel clip receiver 40.Relative closing movement between the two panels is then effected inorder to cause pilot surface 68 of panel clip 30 to engage lockingflanges 48 of panel clip receiver 40, and thereby center projectingtongue 62 with respect to the receiver opening 52. Continued relativeclosing movement causes the tongue 62 through contact between the pilotsurfaces 68 and locking flanges 48 to resiliently angularly rearwardlydisplace locking flanges 48 and thereby permit entry of projectingtongue 62 into panel clip receiver 40. As several serration 70 arepreferably provided, the projecting tongue 62 may be locked in one ofseveral positions with respect to the panel clip receiver 40 toestablish the desired position of the panels 10, 14.

As is shown in FIG. 6, angularly disposed faces 76 of serrations 70 willbe oriented generally parallel to locking flanges 48, and will providefor relative sliding movement between faces 76' and locking flanges 48and rearward resilient deformation of locking flanges 48 as projectingtongue 62 is moved into receiver 40. Forwardly disposed faces 74 willprovide locking engagement with the locking flange 48 and thereby resistrelative separation of the panel clip parts 30, 40. It will also be seenthat the orientation of the faces 74, 76 coupled with the taperedconfiguration of the locking flanges 48 causes the latter tosubstantially completely fill the serration recess 72 and have itsforwardly exposed faces 78 in surface to surface contact with faces 76when locking is effected.

Referring once again to FIG. 3, it is seen that the anchoring wall 60 ofpanel clip 30 is secured in surface to surface engagement withrearwardly exposed surface 22 of first panel 10. The base portion 44 ofpanel clip receiver 40 is secured in surface to surface engagement withouter surface 24 of first panel element 10. With this sort of securementto the respective panels and locking interengagement between panel clip30 and panel clip receiver 40, the first generally rearwardly directedflange 12 of panel 10 cooperates with second panel flange 16 to define aforwardly open rearwardly converging recess 80. As shown, the rearwardend of flange 12 contacts panel 14 and is therefore rearwardlysubstantially coextensive with flange 16. This results in not only anaesthetically pleasing break in the outer surface appearance of the wallconstruction 2 but in addition also permits solely the exterior surfaces20, 24 which are generally the decorative panel surfaces to be forwardlyexposed. Thus, unsightly hardware and unfinished panel surfaces areconcealed from view.

Referring now more specifically to the fragmentary elevational sectionof FIG. 2, it is seen the sill joint is effecting between a starterstrip which is similar in configuration to flange I6 and end sector 18shown in FIG. 3. A panel clip receiver 92 is secured to starter strip 90by means of a suitable fastener. A panel end 94 has a panel clip 96secured to it by a suitable fastener. The panel clip 96 and panel clipreceiver 92 are of the same configuration described above and areinterengaged in the same fashion.

The header portion in the form illustrated provides a panel flange 100which is received within a header channel 102. In effecting this jointthe flange 100 is first inserted into header channel 102. The panel end94 is then rotated inwardly to establish engagement between panel clip96 and panel clip receiver 92. As a result of the serrated projectingtongue configuration of panel clip 92, the sill portion of the panel maybe anchored in the precise position desired by terminating relativeclosing movement between the panel end 94 and starter strip 90.

The relative length of the panel clip 30 and panel clip receiver 40 maybe generally equal. In order to provide maximum adjustableinterengagement, it is preferred to provide a receiver 40 which islonger than the panel clip 30 to fully ensure complete engagement of thetongue serrations. This is the more economical approach as the receiveris preferably made of thinner gauge material. If desired, the clipelements 30, 40 may be substantially coextensive with the length of thepanel ends to be joined, but it is generally more economical andpreferred to provide several independent panel clip assemblies of totalcombined length substantially less than the length of the panel edges tobe joined. While, if desired, the serrations and/or locking flanges maybe made longitudinally discontinuous, maximum locking interengagement isobtained when they are both substantially continuous.

The panel clip 30 and panel clip receiver 40 are effectively restrainedagainst relative separating movement as by withdraw of the projectingtongue 62 from the receiver 40. It will be appreciated, however, that inthe preferred form each element 30, 40 is of substantially uniformcross-sectional configuration throughout its longitudinal extent. Panelclip 30 and panel clip receiver 40 are therefore so configurated as topermit relative free-sliding movement between the same responsive tomovement of the panel to which it is secured. This feature is of greatsignificance as it permits such sliding movement at the joint responsiveto panel expansion and contraction under the influence ofcharges inthermal conditions. The resistance to such relative sliding movementconsists solely of frictional resistance provided by contacting surfacesof the clip 30 and receiver 40. As the extent of contact is kept to arelative minimum, without impairing the structural integrity of thejoints, this frictional resistance will be relatively low. Suchexpansion and contraction provides a desirable thermal break within thejoint structure while maintaining effective joint integrity and anaesthetically pleasing joint assembly which conceals the joint hardwarefrom exterior view and permits exposure of only the decorative exteriorsurfaces of the panels.

While for purposes of illustration specific forms of ribbed plasticpanel structures have been shown, it will be appreciated that thebenefits of this invention may be obtained with a broad range of panelmaterials and structures. Also, for purposes of simplicity ofillustration the panel clip elements have been shown as being secured insurface to surface contact at specific panel locations, but it will beappreciated that these locations may be varied while retaining thebenefits of this invention. The panel to panel joints are providedwithout securement of the panel clip elements to studs or underlyingbuilding framework. It will, therefore, be appreciated that thisinvention provides an economical and effective means of establishing anadjustable yet firm locking joint between adjacent panel elements aswell as between a panel end and a header or sill. MUltiple hardware istherefore eliminated. it will also be appreciated that in addition toproviding an effective joint structure, the joint assembly of thisinvention provides a concealed fastening system that permits movementresponsive to thermal expansion and contraction. It is adapted to bereadily employed with a wide range of panel materials to be simplyjoined in the field without substantial time consumption or the need forspecial equipment or specially trained workers. The components may beeconomically manufactured and presecured to the panel elements at thefactory.

Whereas particular embodiments of the invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details may be made withoutdeparting from the invention as defined in the appended claims.

1. A panel joint construction comprising,

a first panel having a first generally rearwardly directed flangeportion,

a second panel having a second generally rearwardly directed flangeportion terminating in an end sector disposed rearwardly of said firstpanel,

a panel clip receiver element secured to said end sector of said secondpanel having a base portion and two forwardly extending receiversidewalls each terminating in transversely inwardly rearwardly directedlocking flanges,

a panel clip secured to said first panel having an anchoring wall and aprojecting tongue extending into said panel clip receiver between saidlocking flanges,

said panel clip having serrations on opposed transverse walls thereof,and

each said locking flange engaged within a recess in said serrations toresist relative separation of said panel clip from said panel clipreceiver.

2. The panel joint construction of claim 1, including said panel cliphaving said anchor portion secured to said first rearwardly directedflange portion of said first panel,

said panel clip having a transition portion interposed between saidanchor portion and said projecting tongue, and

said forwardly extending receiver sidewalls inclined transverselyinwardly toward each other as they extend outwardly.

3. The panel joint construction of claim 2, including each said firstand second panels having a forwardly exposed face and a rearwardlyexposed face,

said panel clip receiver secured to the outwardly exposed face of saidend sector of said second panel, and

said panel clip secured to the rearwardly exposed fade of said firstrearwardly directed flange.

4. The panel joint construction of claim 3, including at least one ofsaid serrations of said panel-clip-projecting tongue defined by aforwardly exposed face disposed substantially perpendicular to thelongitudinal axis of said tongue and an angularly forwardly directedface originating at the transverse inner portion of said forwardlyexposed face, and

said angularly forwardly directed face oriented generally parallel tothe adjacent locking flanges of said panel clip receiver.

5. The panel joint construction of claim 3, including mechanicalfastening means securing said panel clip to said first panel and saidpanel clip receiver to said second panel,

a plurality of said serrations provided on each said opposed transversewall of said panel clip,

said serrations of one said transverse wall being axially aligned withsaid serrations of said other transverse wall, and

said forwardly extending receiver sidewalls each disposed at an angle ofabout 2 to 15 with respect to planes disposed perpendicular to saidpanel clip receiver base at the origin of said receiver sidewalls.

6. The panel joint construction of claim 5, including said panel clipand panel clip receiver are each composed of metal, and are ofsubstantially uniform cross section throughout their longitudinalextent,

the free end of said projecting tongue of said panel clip hav ingforwardly diverging pilot surfaces adapted to cooperate with saidreceiver locking flanges in guiding said projecting tongue into saidpanel clip receiver, and

the included angle between each said locking flange and each saidreceiver sidewall being about 25 to 45.

7. The panel joint construction of claim 3, including said firstgenerally rearwardly directed flange portion of said first panel andsaid second generally rearwardly directed flange portion of said secondpanel disposed with their outer surfaces generally facing each other,

said first and second rearwardly directed flange portions cooperating todefine a forwardly open, rearwardly converging opening therebetween,

each of said locking flanges of said panel clip receiver being taperedtoward their free ends and terminating in an end having a thicknesswhich substantially completely fills the serration of said tongue withinwhich it is engaged, and

the maximum transverse width of said tongue across said serrations beinggreater than the width of the receiver opening defined by said free endsof said locking flanges.

8. A panel clip assembly comprising,

a generally channel-shaped panel clip receiver having a base portion, apair of spaced forwardly directed sidewalls extending from opposed sidesof said base portion and a pair of angularly rearwardly disposed lockingflanges con' nected to the outer ends of said forwardly directedsidewalls and terminating in free ends spaced from each other anddefining a receiver opening,

a panel clip having an anchoring wall, a projecting tongue havingintegrally formed serrations and a transitional wall connecting saidanchoring wall and said serrated projecting tongue,

said projecting tongue having a rearwardly disposed free end havingforwardly diverging pilot surfaces adapted to enter said receiveropening by engaging and resiliently spreading said receiver lockingflanges,

said serration disposed on opposed sidewalls of said projecting tongue,and

at least a major number of said serrations having a recess defined by afirst serration defining face oriented generally perpendicular to thelongitudinal axis of said projecting tongue and a second serrationdefining face oriented generally parallel to the portion of said pilotsurface on the same side of said longitudinal axis.

9. The panel clip assembly of claim 8, including said projecting tongueis substantially rigid,

said panel clip and panel clip receiver are composed of aluminum andhave a substantially uniform cross section throughout their longitudinalextent,

said outwardly directed sidewalls are each inclined inwardly toward eachother at an angle of about 2 to 15 with respect to planes perpendicularto said base portion, and

the included angle between each said locking flange and the adjacentforwardly directed sidewall is about 25 to 45.

10. The panel clip assembly ofclaim 9, comprising said anchor portion ofsaid panel clip and said projecting tongue of said panel clip disposedin generally parallel spaced relationship with respect to each other,and

said panel clip transition wall having one section disposed generallyperpendicular to said anchor portion and a second portion extendingangularly rearwardly.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 604736 Dated September 14 1971 Inventoflg) Lawrence T. Vance It iscertified that error appears in the aboveidentified patent and that saidLetters Patent are hereby corrected as shown below:

Column 3, line 17, "meal" should read metal Column 4, line 17,"effecting" should read effected line 53, "withdraw" should readwithdrawal Column 5, line 62,

"fade" should read face Signed and sealed this 1st day of August 1972.

(SEAL) Attest:

EDWARD M FLETCHER, JR

ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents M PO-lOSO(10-69] USCOMM-DC 60376-P59 n U 5, GOVERNMENT PRINTING OFFICE I919 O-JGO33l

1. A panel joint construction comprising, a first panel having a firstgenerally rearwardly directed flange portion, a second panel having asecond generally rearwardly directed flange portion terminating in anend sector disposed rearwardly of said first panel, a panel clipreceiver element secured to said end sector of said second panel havinga base portion and two forwardly extending receiver sidewalls eachterminating in transversely inwardly rearwardly directed lockingflanges, a panel clip secured to said first panel having an anchoringwall and a projecting tongue extending into said panel clip receiverbetween said locking flanges, said panel clip having serrations onopposed transverse walls thereof, and each said locking flange engagedwithin a recess in said serrations to resist relative separation of saidpanel clip from said panel clip receiver.
 2. The panel jointconstruction of claim 1, including said panel clip having said anchorportion secured to said first rearwardly directed flange portion of saidfirst panel, said panel clip having a transition portion interposedbetween said anchor portion and said projecting tongue, and saidforwardly extending receiver sidewalls inclined transversely inwardlytoward each other as they extend outwardly.
 3. The panel jointconstruction of claim 2, including each said first and second panelshaving a forwardly exposed face and a rearwardly exposed face, saidpanel clip receiver secured to the outwardly exposed face of said endsector of said second panel, and said panel clip secured to therearwardly exposed fade of said first rearwardly directed flange.
 4. Thepanel joint construction of claim 3, including at least one of saidserrations of said panel-clip-projecting tongue defined by a forwardlyexposed face disposed substantially perpendicular to the longitudinalaxis of said tongue and an angularly forwardly directed face originatingat the transverse inner portion of said forwardly exposed face, and saidangularly forwardly directed face oriented generally parallel to theadjacent locking flanges of said panel clip receiver.
 5. The panel jointconstruction of claim 3, including mechanical fastening means securingsaid panel clip to said first panel and said panel clip receiver to saidsecond panel, a plurality of said serrations provided on each saidopposed transverse wall of said panel clip, said serrations of one saidtransverse wall being axially aligned with said serrations of said othertransverse wall, and said forwardly extending receiver sidewalls eachdisposed at an angle of about 2* to 15* with respect to planes disposedperpendicular to said panel clip receiver base at the origin of saidreceiver sidewalls.
 6. The panel joint construction of claim 5,including said panel clip and panel clip receiver are each composed ofmetal, and are of substantially uniform cross section throughout theirlongitudinal extent, the free end of said projecting tongue of saidpanel clip having forwardly diverging pilot surfaces adapted tocooperate with said receiver locking flanges in guiding said projectingtongue into said panel clip receiver, and the included angle betweeneach said locking flange and each said receiver sidewall being about 25*to 45*.
 7. The panel joint construction of claim 3, including said firstgenerally rearwardly directed flange portion of said first panel andsaid second generally rearwardly directed flange portion of said secondpanel disposed with their outer surfaces generally facing each other,said first and second rearwardly directed flange portions cooperating todefine a forwardly open, rearwardly converging opening therebetween,each of said locking flanges of said panel clip receiver being taperedtoward their free ends and Terminating in an end having a thicknesswhich substantially completely fills the serration of said tongue withinwhich it is engaged, and the maximum transverse width of said tongueacross said serrations being greater than the width of the receiveropening defined by said free ends of said locking flanges.
 8. A panelclip assembly comprising, a generally channel-shaped panel clip receiverhaving a base portion, a pair of spaced forwardly directed sidewallsextending from opposed sides of said base portion and a pair ofangularly rearwardly disposed locking flanges connected to the outerends of said forwardly directed sidewalls and terminating in free endsspaced from each other and defining a receiver opening, a panel cliphaving an anchoring wall, a projecting tongue having integrally formedserrations and a transitional wall connecting said anchoring wall andsaid serrated projecting tongue, said projecting tongue having arearwardly disposed free end having forwardly diverging pilot surfacesadapted to enter said receiver opening by engaging and resilientlyspreading said receiver locking flanges, said serration disposed onopposed sidewalls of said projecting tongue, and at least a major numberof said serrations having a recess defined by a first serration definingface oriented generally perpendicular to the longitudinal axis of saidprojecting tongue and a second serration defining face orientedgenerally parallel to the portion of said pilot surface on the same sideof said longitudinal axis.
 9. The panel clip assembly of claim 8,including said projecting tongue is substantially rigid, said panel clipand panel clip receiver are composed of aluminum and have asubstantially uniform cross section throughout their longitudinalextent, said outwardly directed sidewalls are each inclined inwardlytoward each other at an angle of about 2* to 15* with respect to planesperpendicular to said base portion, and the included angle between eachsaid locking flange and the adjacent forwardly directed sidewall isabout 25* to 45*.
 10. The panel clip assembly of claim 9, comprisingsaid projecting tongue adapted to have its free end extending into saidpanel clip receiver with said free ends of said receiver-locking flangesengaged within recesses of serrations on opposed walls of said tongueand said second serration-defining surface in surface to surface contactwith the generally forwardly facing surface of said locking flanges,said locking flanges tapered toward said free ends, said anchor portionof said panel clip and said projecting tongue of said panel clipdisposed in generally parallel spaced relationship with respect to eachother, and said panel clip transition wall having one section disposedgenerally perpendicular to said anchor portion and a second portionextending angularly rearwardly.